1. Field of the Invention
This invention relates to the field of devices for monitoring and analyzing networks. More particularly, this invention relates to devices for isolating network problems to certain segments on the network.
2. Description of the Problem
A primary objective of telephony providers is to provide users with high-quality voice service through packet networks. Packet networks transmit communication in messages which are commonly known as packets. A packet is a message carrying data for communication between two network endpoints, each having different IP addresses and port numbers. In particular, packet networks carrying voice communications must be closely managed to ensure performance quality acceptable by a user.
Many voice communication and other real-time applications use the Real-time Transport Protocol (RTP) for the transmission of messages. RTP contains quality metrics and is described in Request for Comments (RFC): 1889 and 1890, a series of notes about the Internet by the Internet Engineering Task Force (IETF), which are each incorporated herein by reference. Real-time Control Protocol (RTCP), a subset of RTP and described in detail in RFC: 1889 and 1890, is a network packet that also contains quality metrics, providing information on the quality of a voice communication, or message, at that moment. The headers for these protocols include quality metrics containing current information on jitter, packet loss, and delay. RTCP provides feedback information about the quality of data distribution. Quality metrics are useful to the senders, the receivers and third-party monitors for the discovery of network problems. Any type of network frame may carry quality metric.
Quality metrics are important to network administrators for the anticipation of performance changes and the diagnosis of performance failures. Network administrators use devices known as network analyzers to intercept messages containing quality metrics that are communicated between endpoints in order to assist in the monitoring and analysis of network performance. In order to monitor the traffic between two endpoints on a network, the network analyzer is connected to the network at a location in the network path where messages can be intercepted at a juncture between the two endpoints.
When analyzing network traffic, it necessary for network administrators to determine the source of a problem. When placing a network analyzer between two endpoints on a network, it would be helpful to be able to further narrow the location of a network problem to a segment of the network path.
The present invention solves the above problem by providing the capability to determine the source of a network segment problem. Because the invention is able to provide an operator with information as to the source of a network problem, the operator is better able to manage voice and data services to network users. In one embodiment of the invention, the present invention provides a method for characterizing network segment quality for a segment transmitting messages from a first endpoint to a second endpoint on a network. The network includes first and second segments connected to the first and second endpoints respectively and to each other at a juncture. The method includes the step of receiving messages transmitted between the first and second endpoints at the juncture. The messages include a first set of quality metrics for message transmission from the first to second endpoint for both the first and second segments and a second set of quality metrics for message transmission from the first endpoint to the juncture. Furthermore, the method includes subtracting the second set of quality metrics from the corresponding quality metrics of the first set of quality metrics to calculate a third set of quality metrics representing the quality metrics of the second segment. Still furthermore, the method includes comparing the third set of quality metrics to a first set of segment qualities to characterize the quality of the second segment.
According to yet another embodiment of the invention, the method includes comparing the second set of quality metrics to a second set of segment qualities to characterize the quality of the first segment and comparing the first set of quality metrics to a third set of segment qualities to characterize the quality of the message transmission from the first endpoint to second endpoint.
According to another embodiment of the invention, determining whether the second set of quality metrics are each below associated thresholds for the first segment and indicating to a user there is a problem with the first segment if the second set of quality metrics are not each below associated thresholds.
According to yet another embodiment of the invention, the present invention provides a computer program product for enabling a computer system to characterize network segment quality for a segment transmitting messages from a first endpoint to a second endpoint on the network.
According to another embodiment of the invention, the present invention provides an apparatus for characterizing network segment quality for a segment transmitting messages from a first endpoint to a second endpoint on the network.